Manufacture of crepe rubber shoe soles



July 13 1926.

D. A. CUTLER MANUFACTURE OF CREPE RUBBER snoz sows Filed Ndv. 5, 1925 IN VENTbR Pateiited July 13,1926.

UNITED STATES PVATENT/ OFFICE.

DAVID A. CUTLER, OF WOLLASTON, MASSACHUSETTS ASSIGNOB TO ALFRED HALE RUBBER COMPANY, OIFATLANTIC, MASSACHUSETTS, A CORPORATION OF MASSA- CHUSETTS.

MANUFACTURE 0 3 CREPE RUBBER SHOE BOLES.

Application filed November 5, 1925. sci-m n. cam.

Shoe soles of crepe rubber, that is of pure rubber, unvulcanized, have now achieved a permanent place in the industry, having qualities which commend them to users. especially for sport wear. such soles have had hitherto one objectionable quality, namely, that in long continued use under some conditions, they become smooth on the ground contact surface and slippery on wet pavements or other smooth surfaces. Many efforts have been made to remedy this difiiculty without destroying or impairing other good qualities, but hitherto without success. By the present invention, however, there has been developed a remedy for the difliculty which overcomes the tendency of such soles to become slippery -through long use, but without sacrificing any of the desirable qualities of such soles. In another a plication of the resent applicant, Serial fi o. 40,131, filed one 29, 1925, there is described an improved compound which consists ofranules of cork enveloped in coagulate; latex. Whether such compound has the qualities necessar to enable the shoe sole made entirely o thecompound to endure for a long time all of the conditions of hard use, has not yet been determined fully. However, it has been found that the application toa crepe'rubber sole of an insert of the new compound,;-if the application is made properly, provides a ground contact surface which will not be come slippery through use, while the desirable qualities of the crepe rubber sole are fully greserved. more erence to the accompanying drawings, in which: R I J p Figure 1 is a top view of-a cre or pure rubber shoe sole, with-an anti-slipping in .sert in the forward part of the so e and in the heel.

Figure 2 is a view in section on the plane indiiated by the, broken line 22 of Figure.

The ore rubber sole a, whether as to the portion 0 the sole under the ball of the foot or the portion under the heel, or as to both, is of pure, unvulcanized rubber, secured to the shoe in any approved manner. Applied Nevertheless,

The invention will be llly explained hereinafter with refto, the sole, either under the ball of the foot or under the heel, or in each of these places, is an insert 6, b of a compound which consists of granules of cork enveloped in coagulated latex, as fully described in the application above mentioned. In order that the desirable qualities of the crepe rubber sole may be retained without impairment, itis necessary that the anti-slipping insert be applied to the same without the application of heat and without the use of fastening devices of any kind, and et in such a way that a perfect union of t e insert with the unvulcanized, pure rubber shall be secured. It has been found that this can be accomplished only byfillin the previously prepared cavity in the so e, indicated at c and a, with a mass of granulated cork' mixed with later: without coagulation and then subjecting the mixture topressure while coagulation of the latex proceeds, the pressure being subsequently relieved. If coagulation of the latex has taken place before the mixture is applied, the desirable union .between the mixture and the pure rubber of .only are the desirable qualities of the mix-- ture preserved, but a practically homogeneous union between the mixture and the pure rubber sole is secured, so that no separation takes place even in long continued wear.

I claim as my invention: '1. The improvement in the manufacture of crepe rubber shoe soles, which consists in applyi tothe sole :1. mixture of granulated cork wit uncoagulated latex and subjectin the mixture to pressure while coagulation o the latex proceeds. I

2. The improvement in the manufacture of crepe rubber shoe soles, which consists in forming acavity inthe crepe rubber sole, filling the cavity with a mixture of granulated cork and uncoagulated latex and subjecting the mixture to pressure while coagulation of the latex proceeds.

This specification signed this 2d day of November A. D. 1925. I I

DAVID A. CUTLER. 

